Estimating Annualized Earthquake Losses for the Conterminous United States

Abstract

We make use of the most recent National Seismic Hazard Maps (the years 2008 and 2014 cycles), updated Census data on population, and economic exposure estimates of general building stock to quantify annualized earthquake loss (AEL) for the conterminous United States. The AEL analyses were performed using the Federal Emergency Management Agency's Hazus software, which facilitated a systematic comparison of the influence of the 2014 National Seismic Hazard Maps in terms of annualized loss estimates in different parts of the country. The losses from an individual earthquake could easily exceed many tens of billions of dollars, and the long-term averaged value of losses from all earthquakes within the conterminous United States has been estimated to be a few billion dollars per year. This study estimated nationwide losses to be approximately $4.5 billion per year (in 2012 dollars), roughly 80%of which can be attributed to the states of California, Oregon, and Washington. We document the change in estimated AELs arising solely from the change in the assumed hazard map. The change from the 2008 map to the 2014 map results in a 10% to 20% reduction in AELs for the highly seismic states of the Western United States, whereas the reduction is even more significant for the Central and Eastern United States.